Sawmill-carriage.



No. 839,338. v-PATENTED'DEG. 25, 1906.

` V J. TORRENT.

SAWMILL CARRIAGE; APPLIOATION FILED J'U'LYzs, 1905;

" :suns-annu 2.

Jah/175mg I- l nventor THE mmm: PETERS ca., wAsHlNcT/w. u. c.

. Attorneys PATENT, clarion JOHN ToRRENr'oF MUsKEGoN, MICHIGAN.

SAW-MILL- l )Specification of Letters Patent.

CARRIAGE.

Patented Dec. 25, 1906.

Appia-.cion nea Juiyz, 1905. serai'No. 271.200;

r Tod/ZZ whom it may concern.-

Sawmill-Carriage, of `'which the `following isa speciiication. c;

This invention relates lto sawmill carriages, and in particular to fluid-pressure- Ic actuated mechanismffor driving or feeding the carriage through the nmedium of a piston anda piston-rod. A v l k'The object of the present. invention is to cushion the piston at each limit ofiits stroke, and therebyk absorb the jars 'which are incident to the stopping and changing of direction of movement of the piston. i Vlhile the present cushioning means vis partially active at the limit of each stroke of the zo piston, itis particularlyT designed as an emergency device and does not come into i-ull operation until the piston passes its usual limit by reason of breakage of the piston-rod or by reason of the engine getting beyond the con 2 5 trol of the operator.: It is therefore the main purposeof the cushioning means to prevent the piston Jfrom striking the outer end of t the cylinder shouldy said piston travelbeyond its normal limit, thereby to prevent damage 5o to the ...end of the -cylinder and toother partsv of the apparatus. j v

- Withv these and other objects in viewthe present invention consists in the combination and arrangement of parts, as willbe hereinj 3 5 after morefully described, shown inthe ac-` and. particularly y companying drawings,

pointed out in the appended claims, it being understood that changes in the form, proportion, size, and minor details may be made 4o within the scope of the claims without departing 'from the spirit or sacrificing any ofthe advantages of the invention. t

Inv the accompanying drawings, Figure lis a perspective view of a sawmill-carriage and uid-pressure-eed mechanism equipped with j the cushioning means of the present invenc tion. Fig. 2 is alongitudinal sectional view vlof lthe carriage at its forward limit. Fig. 3 is an 't enlarged fragmentary sectional view f5@ illustrating the cushioning-springs located in opposite endsv of the cylinder. t

y Like characters of reference designate corresponding parts in each and every figure of thedrawi'ngs.

kFor the purpose of illustrating the application and operation of the present invention a y sawmill carriage 1 of any common yor approved form has been shown in the accompanying drawings, said carriage being mounted to work back and forth upon guideways 2, so as to approach lar saw 3.

i v The means for working the carriage back andiorth consists of a cylinder 4, supported independently of the carriage and beneath the same inrearof the saw. Within this cylinder there is a piston 5, having a pistonrod 6 working through a suitable stuffing-box 7 kthe'rear end 'of the cylinder, the outer eX- tremity of the rod being connected to the rear end of the carriage in any suitable man- 'ate hanger. (Shown at 8in Figs. 1 and 2 of the drawings.) Steam orV other huid-pressure is admitted to the ends of the cylinder through the medium of'a four-way controlling-valve 9, included in the service-pipe, whichhas one cylinder and" another branch 11 leading to the right-hand end of the cylinder. The four-way valve 9 is under the control of the sawyer by means 'of any suitable mechanism, Yincluding a connecting-rod 12.

' In practice steam being admitted to one end of the cylinder the piston will be driven to the opposite end thereof, and through the carriage will e moved with the piston. When the piston has completed its movement in one direction, vthe controlling-valve is actuated to admit steam to the other end back to its original position, 'and thus move the carriage back to its original position. During'the back-and-forth movement of the carriagek the latter acquires considerable momentum, which added'to the sudden stopping of the v'piston at each limit of its movement produces jars which are exceedingly injurious to the ycarriage and other parts of the sawmill. To'obviate this jarring of the sawmill-carriage and other parts of the mill, a helical spring 13 is provided within'each end ofthe cylinder, so as to receive the impact of the piston, and thereby cushion the latter and absorb the usual jars incident to the sudden stopping and change of direction of movement of the piston. By the employment of thesprings or cushioning devices the piston, and consequently the sawmill-carriage, are not suddenly stopped, but gradually stopped bythe resistance of one or the and recede from the .circubranch l() leading to the left-handend of the i medium of the iston-rod 6 and hanger 8 theY ner-for instance, by means of anappropriof the cylinder, and thereby drive thepiston IOO other of the springs, and therefore none of the mechanism of the mill is subjected to violent jars, which insures an easy and regular operation of the carriage.

It will here be explained that while the inner end of each spring is in the ath of the piston the latter normally stops be ore the full resistance of the spring is encountered; but should the piston travel beyond its normal limit through any cause the full cushioning effect of the spring will be exerted upon the piston to prevent contact of the latter with the end of the cylinder, whereby breakage of the end of the cylinder is prevented and all jar is absorbed by the spring, which prevents damage to the other portions of the mill.

From the foregoing description it will be understood that theapplication of the present invention requires no change or alteration whatsoever in the sawmill-carriage nor in the steam-actuated feed mechanism therefor, nor does the application of the invention interfere with or change the operation of the mill, but, on the other hand, renders the operation thereof smooth and regular.

Having thus described the invention, what is claimed is- 1. A fluid-pressure cylinder having combined inlet and exhaust ports located inwardly from its ends to provide terminal spaces 'for entrapment of huid-pressure to cushion the piston, and emergency cushionin@ devices within the cylinder comprising helical springs each permanently abutting a head of the cylinder and disposed to become active when the piston exceeds the limit of its movement at either end of its stroke.

2. The combination of a reciprocatory carriage', a fluid-pressure cylinder mounted independently of the carriage and provided with combined inlet and ex iaust ports disposed inwardly from its ends to provide terminal spaces for entrapment of Huid-pressure, a piston working in the cylinder, a piston-rod connected to the carriage, and helical springs within each end of the cylinder and disposed for engagement by the piston when it exceeds its limit of movement at either end of its stroke.

In testimony that I claim the foregoing as my own I have hereto aflixed my signature in the presence of two witnesses.

JOHN TORRENT.

Witnesses t JOHN B. BARLOW, IDA E. NYLUND. 

